CN103769799A - Method for forging high cone stepped forging piece with axial hole - Google Patents

Abstract

The invention discloses a method for forging a high cone stepped forging piece with an axial hole in the technical field of automobile manufacturing. The method comprises the following steps: sequentially performing upsetting and die forging treatment on a thermal die forging press, and obtaining a semi-finished forging piece of which the shape is the same as that of a final forging piece and the height is lower than that of the final forging piece; punching on a clipping press, so as to enable the lower half part of a hub to reach a specified size; and finally, punching gross weight on the clipping press, removing flashes, and obtaining the high cone stepped forging piece with the axial hole. The problems of high material consumption and energy consumption in the prior art are solved, the dimensional accuracy and quality of the forging piece are greatly improved, the service life of the die is prolonged, a forging piece with an axial through hole can be obtained, the diameter d of the axial hole with the smallest diameter of the through hole is equal to 25-30mm, and a depth-diameter ratio is 3-3.5.

Description

With the forging method of the high frustum of axial hole rank swaged forging part

Technical field

What the present invention relates to is a kind of method of tractor and field of automobile, specifically a kind of forging method with the high frustum of axial hole rank swaged forging part.

Background technology

In tractor caterpillar transmission shaft, gear clutch part is flanged (FLGD) cone hub and through hole.Obtaining like parts most effectual way is stress metal processing, the good polishing machine that can obtain part high strength index and cause due to the sclerosis of material by such technique, and have sufficiently high precision and productivity ratio concurrently, and the loss of metal is also little.But in reality, seldom use this technique.Because the size in hole is less than normal ,≤30mm hole generally can not punching, is often swaged into blind hole, cannot realize by traditional open die forging, impressing forging method.Certainly, this has not only increased the loss of metal, and has increased machining amount.

Through the retrieval of prior art is found, Chinese patent literature CN1628921, open day 2005-06-22, discloses all fiber forging forming technology and the mould of a kind of bogie hub axle tube.Be characterized in: adopt solid handful material, once heated the extrusion molding of hub axle tube outer surface and deep hole, thereby obtain the full fibre metal streamline distributing vertically, the complete extrusion molding of endoporus, no longer machined.But this technology adopts pressing method shaping endoporus, extruding endoporus power is more much bigger than punching power, therefore, needs plant capacity also much bigger than punching apparatus; And, generally want >=30mm of the aperture of extrusion deep hole, if≤30mm, drift very easily fractures.

Wang Lin, Zhang Fengjun disclose the Rollover technique that a kind of step forging stock is shaped in " Technology of Forming by Loose Tooling & Die Design of Stepped Forgings " (" CMET. forging and stamping equipment and manufacturing technology " 04 phase in 2004), comprise blanking, jumping-up, shaping, punching four procedures, first by the bar section of being cutting into, then heating, free compression, puts into shaping dies and is shaped.After the demoulding, put into punching die punching.But defect and the deficiency of this technology are: the step forging that is only applicable to endoporus 30<d<40, whole forming process is the Compound Extrusion that integrates forward extrusion, backward extrusion, radial compression, its resistance of deformation is large, and therefore required equipment tonnage is larger.

Summary of the invention

The present invention is directed to prior art above shortcomings, a kind of forging method with the high frustum of axial hole rank swaged forging part is proposed, overcome material consumption and the large problem of energy resource consumption in prior art, dimensional accuracy and quality and the die life of forging are increased substantially, can obtain with axially extending bore forging, and the axial hole of through hole minimum diameter is d=25～30mm, aspect ratio 3～3.5.

The present invention is achieved by the following technical solutions: the present invention includes following steps:

1) on hotdie forging press, carry out successively jumping-up and die forging processing, obtain with finish-forging part same shape and height lower than the forging semi-finished product of finish-forging part;

2) punching on clipping press, makes wheel hub the latter half reach given size;

3) on clipping press, wash away gross weight and excise overlap.

Between the punching COEFFICIENT K adopting in described punch process and the surface-supported lateral area of blank, proportionate relationship meets:

$K\&le;1.143\frac{h}{D}[(2\tan \mathrm{\&alpha;}+0.6)\&times;\ln \frac{1}{1-2\frac{h}{D}\tan \mathrm{\&alpha;}}+\tan \mathrm{\&alpha;}],$ Wherein: $K=\frac{f}{F}=\frac{d^2}{D^2},$ α is die wall gradient, and f is axis hole cross-sectional area, and F is that cone hub big diametral plane is long-pending, and h is tapering part hub height, and D is section diameter of the large end of tapering part wheel hub;

for relative altitude; Thereby make drift secure support die skew wall, and punching COEFFICIENT K is motionless in being still trapped in die upper portion with wheel hub the first half of flange when the punching, and can be drawn in die lower portion because punching drives.Equate to calculate with hollow forging volume according to solid blanks volume, therefore punching coefficient permissible value is only relevant with die wall gradient α.

Described die wall gradient α is preferably 3～5 °, in the time of 3 ° of α <, has reduced blank surface sides and has supported, and metal starts to be drawn into die, even under little COEFFICIENT K condition; As 5 ° of α > and time, at the convergent position of die Lower Half, cause very big difficulty to metal flow below drift, punch process forwards extrusion process to, at this moment just need to complete crowded hole process than the much bigger extruding force of punching.

Described punching COEFFICIENT K is preferably 0.18～0.33, and more preferably 0.25～0.3; At K > 0.3～0.33 and adopt short blank

time, increase metal and be drawn into die probability; And when adopting high blank

shi Chongkong power sharply increases, and punch process is transferred to extrusion process.The minimum punching coefficient that allows is limited to pierce punch longitudinal stability.

Technique effect

Compared with prior art, the present invention, in metal stresses state sketch map, compares with hot extrude pressure, has greatly reduced punching power on the drift of punching.This not only guarantees that punch process does not complete on the large main frame of tonnage, and has reduced punch wearing and tearing and can on clipping press, wash away subsequently gross weight trimming.

Accompanying drawing explanation

Fig. 1 is gear clutch forging drawing;

In figure: a is current technology, b is technique of the present invention, and c is Fig. 1 b enlarged diagram;

In Fig. 1 c: f is axis hole cross-sectional area, F is that cone hub big diametral plane is long-pending, and h is tapering part hub height, and D is section diameter of the large end of tapering part wheel hub; S is outer surface of cone, i.e. the stayed surface of blank; The die inwall that S is corresponding, i.e. drift secure support die inwall; Dotted portion is parts profile line, and hacures are hatching.

Fig. 2 is gear clutch die forging work step schematic diagram;

In figure: a is jumping-up work step, b is die forging work step, and c is punching work step, and d is punching the wad, trimming work step.

The specific embodiment

Below embodiments of the invention are elaborated, the present embodiment is implemented under take technical solution of the present invention as prerequisite, provided detailed embodiment and concrete operating process, but protection scope of the present invention is not limited to following embodiment.

Embodiment 1

Use this method, with 40Cr be material, designed hollow tooth-shape clutch die-forging of forge pieces technique.As shown in Figure 1, a is current use technique forging drawing, and b and c are the present embodiment forging drawing.

The existing production technology of gear clutch forging part is carried out on non_mechanical die forging production line on nominal pressure 25MN hotdie forging press, 95/hour of average die forging productivity ratio.Die forging blank heats in cell-type flame furnace, and it is impossible under these process conditions, obtaining axial hole.

As shown in Figure 2, in the present embodiment:

Work step 1, is placed in blank on 16MN hotdie forging press after Frequency Induction Heating;

Work step 2, carries out jumping-up as shown in Figure 2 a, obtains flange wrinkle shape; Then carry out die forging as shown in Figure 2 b, obtain with overlap semi-finished product forging;

Work step 3, as shown in Figure 2 c, on 2.5MN clipping press to rushing axial hole with overlap semi-finished product forging; Finally carry out trimming as shown in Figure 2 d, die-cut gross weight.

In above-mentioned work step, semi-finished product die-forging of forge pieces power and punching power obtain according to " Principles of Metal Forming (Wang great Nian edits China Machine Press, June nineteen eighty-three " computational methods, are specially:

D=74.92 in the present embodiment, d=30, has the punching unit pressure p=σ of forcing press in punch process _s(1.5+1.1lnD/d)=σ _s(1.5+1.1ln74.92/30)=2.51 σ _s; And as adopted existing extrusion process, backward extrusion unit pressure $p={\mathrm{\&sigma;}}_s[\frac{D^2}{d^2}\ln \frac{D^2}{D^2-d^2}+(1+3\mathrm{\&mu;})(1+\ln \frac{D^2}{D^2-d^2})].$

Obtain σ _s[62.37ln1.0163+ (1+3 μ) (1+ln1.0163), i.e. σ _s[10.104+1.0162 (1+3 μ)].

When forge hot, with coefficientoffrictionμ=0.3 substitution, obtain punching unit pressure p=10.104+1.93=11.95 σ _s, wherein: σ _sfor forging material yield stress.From above Quantitative Comparison, prior art is 4.78 times of this method hole-punching method to Same Part employing backward extrusion method unit pressure.And can moving on to 2.5MN forcing press from 25MN forcing press by drill process, this method completes.

Further, reasonably contour forging technique is achieved on transfer matic, and transfer matic comprises automatic induction heating apparatus, die set, hotdie forging press model K Б 8042, nominal pressure 16MN; Clipping press nominal pressure 2.5MN.Approximately 290/hour of average die forging productivity ratio.In table, list gear clutch forging conventional production methods and this method comparison.

The comparison of table 1 gear clutch forging the old and new process economics index

Technology category	Main forging machine nominal pressure (MN)	Forging quality (kg)	Material consumption (kg)	Productivity ratio (pcs/h)
					Traditional handicraft	25	5.5	6.62	95

The present embodiment

16

4.8

5.51

290

The hot forging technique that design tooth profile clutch is new, this forging cone hub place is with flange and axially extending bore.Compared with prior art, this method has guaranteed:

1) reduce material consumption and energy resource consumption, increased the labor productivity of forging part;

2) the accurate location of dimensional accuracy and the quality, particularly semi-finished product forging that has improved forging in punching concave die, has reduced the Wall-Thickness Difference of hollow wheel hub widely;

3) Small-deep Hole is shaped, and is impossible according to traditional contour forging technique;

4) improved die life.

Claims (5)

1. with a forging method for the high frustum of axial hole rank swaged forging part, it is characterized in that, comprise the following steps:

1) on hotdie forging press, carry out successively jumping-up and die forging processing, obtain with finish-forging part same shape and height lower than the forging semi-finished product of finish-forging part;

2) punching on clipping press, makes wheel hub the latter half reach given size;

3) on clipping press, wash away gross weight and excise overlap;

Between the punching COEFFICIENT K adopting in described punch process and the surface-supported lateral area of blank, proportionate relationship meets:

$K\&le;1.143\frac{h}{D}[(2\tan \mathrm{\&alpha;}+0.6)\&times;\ln \frac{1}{1-2\frac{h}{D}\tan \mathrm{\&alpha;}}+\tan \mathrm{\&alpha;}],$ Wherein: $K=\frac{f}{F}=\frac{d^2}{D^2},$ α is die wall gradient, and f is axis hole cross-sectional area, and F is that cone hub big diametral plane is long-pending, and h is tapering part hub height, and D is section diameter of the large end of tapering part wheel hub;

for relative altitude.

2. method according to claim 1, is characterized in that, described die wall gradient α is 3～5 °.

3. method according to claim 1, is characterized in that, described punching COEFFICIENT K is 0.18～0.33.

4. according to the method described in claim 1 or 3, it is characterized in that, described punching COEFFICIENT K is 0.25～0.3.

5. method according to claim 1, is characterized in that, the unit pressure p=σ of the described required clipping press of punching _s(1.5+1.1lnD/d), wherein: σ _sfor forging material yield stress.

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